As AppleInsider's Sam Oliver points out, Apple is still using Samsung's 45nm chip process to fab its indigenously designed A5X CPU that powers the wildly popular iPad.

Perhaps not unsurprisingly, Apple is wary of newer chips built on smaller production processes, fearing potential supply constraints that could threaten iPhone and iPad sales. It is unclear when Cupertino plans on making the inevitable jump to 28nm, although the company has already deployed 32nm A5 chips in its third-gen Apple TV and the new iPad 2.

While Apple's primary chipmaker remains Samsung, Apple reportedly signed a major foundry agreement with TSMC in 2011 to build future ARM-based mobile processors.